The relationship between malnutrition early in life and subsequent mental retardation in man has been suggested by many workers. However, the coincidence of social and psychological deprivation with early nutritional deprivation precludes assignment of a cause and effect interaction to this relationship. Thus, the need for animal studies carefully designed to demonstrate the mechanism of such an effect is evident. This Program Project is a coordinated multidisciplinary study of the role of early maternal protein undernutrition on the ontogeny of the structure and function of CNS of the albino rat. It is hoped that the results obtained in this Project will shed light on the possible role of early malnutrition on the etiology of some forms of mental retardation in man. The following organizational components and disciplines will participate in this series of independent but clearly interrelated studies which will potentiate and support each other: Divisions of Neurochemistry, Neurophysiology, Neuropharmacology, Neuroanatomy, Nutritional Biochemistry and Behavior.